Sheet stacking and delivering machine



Oct. 13, 1953 N MCCLURE ETAL SHEET STACKING AND DELIVERING MACHINE FiledMay 14, 1948 3 Sheets-Sheet l .dgl

Oct, 13, 1953 N. MCCLURE ETAL SHEET STACKING AND DELIVERING MACHINEFiled May 14, 19.48

3 Sheets-'Sheet 2 Oct. 13, 1953 N. MCCLURE :TAL 2,655,272

SHEET STACKING AND DELIVERING MACHINE 5 Sheets-Sheet 3 Filed May 14,1948 Patented Oct. 13, 1 953 SHEET STACKING AND DELIVERING MACHINENicholas McClure, Chicago, I ll., and Samuel D. Stacy, Grand Rapids,Mich., assignors to Amer-y ican Box Board Company, Grand Rapids,iMich.,a corporation of Michigan Application May 14, 1948,Seria1No. 26,948

1,0 Claims- 1 In the manufacture of double faced corrugated board andother types of stiff sheet ma.- terial, a plurality of wide sheets whichmay or may not have been slitted lengthwise, are delivered in successionfrom cut-off mechanism and assembled in superposed relationship to formstacks.

With constantly increasing operating speeds on corrugating units, thespeed at which the sheets are delivered at the cut-off end is becomingcorrespondingly greater. Modern machines for making double facedcorrugated board deliver the sheet material through the cuttingmechanism at a speed of 350 to 500 linear feet per minute, and a seriousproblem is presented in regard to stacking and disposing of theresulting product. This has now reached a point where men can no longerpick up the separate sheets by hand and load them on trucks, as was oncecom.- mon practice.

Various types of sheet handling .equipment have been tried, andexperience has indicated very definitely that it is desirable to deliverthe sheets in small stacks or batches which, Vdepending upon sheet sizeand operators preference, contain Afrom l5 to as many as A25 sheets perbatch.

The present invention relates 't0 .machines ,fer receiving and stackingsuch stiff vsheets or boards, andas important features, provides meanswhereby the boards as delivered, are slowed down in speed, formed into astack, and batches of predetermined V'height `are removed at relativelylow speed and in succession from the bottom of the stack withoutinterfering with the continuous delivery of further sheets -to the topof the .pile. If the vsheets have been slitted lengthwise there will bea plurality of such batches side by side which may be separately pickedup and loaded on a-truck or pallet.

In carrying out the invention there is provided a vertically disposedstop member in the path of movement of the sheets and spaced above thesupporting table or platform, and a pusher of a height only slightlyless than the height of the stop above the table, which moves :along thetable to engage the end of the sheets forming the lower portion of thestack and to push a batch of the sheets beneath the stop and deliver thebatch from the table, whereupon the remaining boards in the stack dropto the table.

The stop is preferably vertically adjustable, so as to leave the correct.amount of space therebeneath for the pusher to freely pass and to ad.-vance a batch of a predetermined height, and is 2 adjustable lengthwiseof the table so that it may be'positioned in accordance with the lengthinto which the sheets have been cut at the cutoff mechanism.

As another feature of the invention the pusher is carried by endlessmembers such as chains, so that after a batch has been pushed beneaththe stop, the pusher returns beneath the table preparatory to pushingout another batch. The pusher is preferably operated intermittently andis started' after sheets have accumulated on the lower edge of thetablev to a height of at least about twice the height of the pusher.After a batch has been pushed out from the bottom and beneath the stop,the pusher may remain at rest below the upper surface of the table untilthe stack again reaches the predetermined height. Preferably means areprovided for slowing down the sheets after they leave the cut-off, andas they are passing onto the stack, so that they will be inpartiallyoverlapped relationship and will not strike the stop at toohigh a speed.

Preferably means are provided for speeding up each batch after it isfreed from the superposed sheets of the stack, so that the batch willnot interfere with the swinging of the pusher to a position below thelevel of the table preparato-ry to the return movement for pushinganother batch.

The stopping and starting of the pusher may be controlled by suitableswitches, the starting switch being controlled in accordance with theheight of the stack accumulated in advance of the stop, and the stoppingswitch may be of any suitable type and automatically operated when thepusher reaches a predetermined position in its return movement beneaththe table.

In the accompanying drawing onlywone .embodiment of the invention hasbeen illustrated, but it will be obvious that many changes maybe made inthe details of construction and arrangement of the parts withoutdeparting from the scope of the invention. In these drawings:

Fig. l is a plan View o f the machine.

Fig. 2 isa side elevation.

Fig. 3 is an endelevation of the .discharge end.

T- he remaining figures are 4on a larger scale.

Fig. 4 isa plan view lof a portion of the means 'for adjusting ythe stopalong the table. f

Fig. 5 is a section on the line 5 5 of `et.

Fig. 6 is a top .view of a portion of the table showing one end portionAof the pusher `for advancing a batch, and the driving means therefor.

Fig. 7 is a view similar to Fig. .6, and showing 'a central portion ofthe pusher.

Fig. 8 is a section on the line 8 8 of Fig. 6.

Fig. 9 is a section on the line 9 9 of Fig. '1.

Fig. 10 is a vertical section showing a means for vertically adjustingthe sheet stop, said section being taken on the line lill-I0 of Fig. l.

Fig. 11 is a vertical section showing the starting switch for the batchadvancing means, said section being taken on the line H--Il of Fig. l.,and

Fig. l2 is a wiring diagram.

Mechanism involving the present invention may be used in connection withany suitable machine which forms the stiff sheets, cuts them intosections, and delivers them in succession. The sheet forming means maybe a machine for making double faced corrugated paper, and the sheetswhich are cut off at the delivery end of the machine are preferablyslowed down before reaching the table. As shown, a conveyor is lprovided onto which the sheets drop, and by means of which the cut offsheets are advanced at a somewhat lower speed than the speed at whichthe stiff sheet is being produced. Thus the successive sections asadvanced will be in a somewhat overlapped position, and the sheets willtravel onto the stack on the table at a lower speed than that at whichthey were produced. If desired, the pulley 2i of the conveyor 2B may bevertically adjustable, for instance by pivotally mounting an arm 22which supports the pulley 2 l, A

Our improved machine includes a table or platform 23 disposed beyond theconveyor 20, and this is preferably subdivided longitudinally intosections to facilitate the operation of the pusher which moves over thetable. As shown in Figs.

6 to 9, this pusher is in the form of an angle iron extendingtransversely of the platform and having a horizontal flange 25 slidableon the table and a vertical flange 26 which engages the ends of asuicient number of the sheets to form the desired batch and push themalong the table. This angle iron pusher preferably has rollers 26aengaging the table and longer rollers 26h engaging the underside of thestack as a batch is being pushed beneath the sheet stop as shown in Fig.2. The pusher is preferably operated intermittently, and may be operatedby endless members such as chains 21 traveling around sprocket wheels 28and 29 at the receiving and delivery ends of the table. The upper run ofeach chain is disposed below the upper surface of the table, and in orbelow a longitudinal slot 30 in the table, and the pusher is secured tothe chains by lugs 24 (Fig. 8). The table may also be provided with anintermediate slot 3 I, and the pusher may have a depending ange 32 inwhich are journaled rollers 33 which engage the underside of the table(Figs. 7 and 9).

For supporting the sheet stops there are provided a bridge 34 and atransverse bar 3B rigid therewith. These are slidable along side framemembers 35 and are supported by or above the table. One or both of theside frame members 35 carries a rack bar 31 with the teeth thereof onthe lower side, and the bridge has supports 34 for a transverse shaft 38having a pinion 39 engaging this rack bar. On the outer end of the shaft38 is a gear 40 engaging a worm gear 4l keyed to and slidable along ashaft 42. Thus by any suitable means, such as a hand wheel 43, the shaft42 may be rotated to rotate the shaft 38, and the pinion 39 will travelalong the rack bar to adjust the entire bridge along the table and to aposition selected in accordance with the length of the sheets.

The transverse bar 36 which is rigidly secured to and movable with thebridge 34, carries a plurality of sheet stops which may be of the typeshown in Fig. 10. If the delivered sheets be slitted lengthwise intostrips these stops may be adjusted along the bar so that there will bea. stop in the path of movement of each stack of strips. Each sheet stopmay be a vertical bar 45 which is supported by and adjustable verticallyand also along the transverse bar 36. As shown, each stop has a flange46 through which extends an adjusting screw 41, the head held beneath aange 48 connected to a sleeve 49 slidable along the bar. The sleeve 49also has a set screw 50 whereby the sleeve and the sheet stop may beheld in adjusted position along the length of the bar 36.

The lower end of each sheet stop 45 is held at a xed distance above thetable 23 by means of the screw 41, to permit the pusher to passtherebeneath. The sleeve 49 may have a dovetailed vertical groove in oneside thereof, in which the vertical bar or stop 45 may slide duringadjustment for batches of different heights, and which holds the baragainst sidewise or tilting movement.

In normal running of the machine it is not necessary to move the bridgeand sheet stops along the table, but adjustment is made in accordancewith the frequency of the cut-off mechanism of the sheet, so that thestops will be at the proper place along the table and in respect to thelength of the sheets being delivered against them.

In operation the sheets are delivered by the conveyor 20 and will travelby their own momentum until they come into engagement with the sheetstops 45. When the stack has been built up to approximately apreselected height the pusher removes a batch of sheets from the bottomof the stack. This pusher, as previously noted, slides along the table,and its vertical flange 2B is of a height but slightly less than thedistance to which the sheet stops are adjusted above the table. The twochains 21 in the slots 30 are connected to the pusher, and the chainsare driven by a motor 5l through a chain 52 to a sprocket 53 on atransverse shaft 54 which has the sprocket wheels 29 secured thereon.The motor is intermittently operated, and when the motor is at rest thepusher is on the lower run of the chains 21 beneath the table, and. inthe position illustrated in dotted lines in Fig. 2.

For starting the motor when the stack of sheets on the table reaches apredetermined height above the lower ends of the stops, there isprovided a starting switch 55 which may be vertically adjusted by asupporting rod 56 and set screw 51, and in respect to the transverse bar36, and disposed between two of the stops. The switch has an operatinglever 58 pivoted at its lower end and normally extending out beyond thevertical plane of the stops. As successive sheets come to rest againstthe stops the height cf the stack increases until sheets reach the lowerend of the switch lever, and then each successive sheet as deliveredpushes the switch lever inwardly slightly. The circuit is eventuallyclosed at the switch, and the motor is started. The pusher is carried tothe left from the position shown in dotted lines in Fig. 2, around thesprocket wheels 28, and onto the table 23,V engages the edges of thesheets forming the lower portion of the stack, and a batch is pushedout.

S The superposed sheets then drop to the :table below the switch.

The switch 55 is merely -a starting switch and the motor does not stopwhen the superposed sheets drop to :the table. When the pusher reachesthe sprocket wheels 28 it swings around and returns along the lower runof the chains.

In order to permit this swinging of the sheet pusher there is provided.a roller 59 spaced a short distance beyond the sprockets 29, and at suchan elevation as to support the batch as it passes thereover. This roller59 is driven from the motor 5| and has a higher peripheral speed thanthe speed of advancement of the pusher. Thus, when the pusher passesbeneath the sheet stops and the batch no longer serves to support anysuperposed sheets, the batch resting on the roller 59 will be advancedat a slightly higher rate than the speed of movement of the pusher, sothat by the time the rear end of the batch passes over the axis of thesprockets 28, it will have been advanced beyond the pusher, and thepusher will be free to swing around the sprockets and to the lower run.The pusher is then stopped at any convenient point along the length ofthe return movement beneath the table. As shown, a stop switch 60 ismounted on the under side of the table and has a switch lever 6|depending into the path of the pusher. Thus, when the pusher engages theswitch lever, the current to the motor will be cut off, and the pusherwill come to a stop at a short distance beyond the switch. The electriccircuit of the motor, with the two switches therein, may be of thecharacter shown in Fig. l2, so that after the pusher has been stoppedbeneath the platform by the action of the switch 60, that switch mayclose without restarting the motor, and the motor is not started againuntil the switch 55 or the switch 69 is again closed, when the stack ofsheets on the table has been built up to the required height, or whenthe operator desires to deliver a smaller batch.

In Fig. 12 there is shown a wiring diagram of a control circuit whichmay be employed. The A. C. motor 5| has three feed lines 63, 64 and 65.,with movable contacts 63a, 64a and 65a, which are operated by acontactor holding coil 66 in a branch line 61 connecting the lines 64and 65. In the branch line, and in series with the coil and in parallelwith each other, are the starting switch 55, a circuit closer 68operated by the coil 66, and preferably a foot operated switch 69located at the delivery end of the machine so that if desired, theoperator may start the pusher to deliver a batch of sheets, even thoughthe batch is not high enough to automatically close the switch 55.

When :the batch gets high enough to close the starting switch 55, orwhen the operator closes the foot switch 69, a circuit flows through theline G1 and the coil 66, whereupon the circuitv is closed at 63a, 64a,65a and 68 by the action of the coil 66, and the motor starts. Eventhough the switch 55 or the switch 69, or both, be immediatelythereafter opened, the coil will remain energized and the contacts 63a,64a, 65a. and 68 held closed. When the stop switch B is opened thecircuit :to the coil is opened, the contacts operated by the coil areopened, and the motor is stopped.

The sheets as delivered from the cut-off may be somewhat warped, and tocounteract warpage it is customary in loading a truck or pallet toreverse the position of each batch in respect to the previous one, insuch a manner that the concave end of a batch faces the convex endy of apreceding batch. With prior machines and with the present high speeds,the handling of the sheets from the take-ofi table to the trucks orpallets means much Work and ei'lort. The sheets have to be not onlystacked, as above described, to counteract warpage, but have to bestacked neatly. The operator has to watch until a suicient number ofsheets have accumulated, and each batch of 25 to 35 sheets has to be seton end and the sheets have to be shifted and pushed so that the ends ofthe sheet in the batch are even with each other before being lifted ontothe truck. The number of sheets in a batch Varies a great deal, becauseeach batch has to be taken 01T the table to permit sheets to accumulateand form another batch.

Our improved mechanism overcomes a great many Aof these troubles. Itpiles up the sheets evenly, and always delivers `the same number ofsheets to the operator on the take-off table, and leaves sufcient timeto load them on the truck or pallet.

Having thus described our invention what we claim vas new and desire tosecure by Letters Patent is:

1. A machine for stacking and delivering stiff sheets, including atable, means for projecting sheets ledgewise in succession to form astack, a stop in the path of the sheets and spaced at a predeterminedelevation above said table and in the path of movement of said sheets,and a pusher of a height substantially equal to the elevation of thelower side of said stop and movable over said table in one direction andbeneath said stop to push out a batch of sheets from the bottom of thestack, and movable in the reverse direction beneath said table.

2. A machine for stacking and delivering stiff sheets, which includes astationary table, endless chains having superposed runs lengthwise ofsaid table and therebeneath, a pusher on said table and connected tosaid chains, and movable over said table in one direction and beneathsaid table in the opposite direction, lmeans for automatically stoppingsaid chains and pusher with the latter in a predetermined position belowthe table, and means for automatically starting said chains and pusherwhen a stack of sheets of predetermined height has accumulated on thetable, to remove from the bottom of said stack a batch of sheets.

3. A machine for stacking and delivering stiff sheets, which includes atable onto which the sheets are delivered in succession to form a stack,a stop in the path of movement of said sheets and spaced at apredetermined elevation above said table, a pusher movable over saidtable and beneath said stop to push out a batch of sheets from thebottom of the stack, a motor for operating said pusher to move itlengthwise across the table and back beneath the table, a switch forstarting said motor when the batch reaches a predetermined height, andmeans for stopping said motor with said pusher beneath the table.

4. A machine for stacking and delivering stiil. sheets, including atable having a slot lengthwise thereof, a chain having an upper runjuxtaposed to said slot, a pusher movable over said table and connectedto said chain, a stop above the table and intermediate of the ends ofthe latter, and having its lower edge at an elevation but slightlygreater than the plane in which the upper edge of said pusher travelswhen moving over said table, means for operating said chain to advancesaid pusher and deliver a batch of sheets beneath said stop when thestack reaches a predetermined height, and means for advancing the batchat a faster speed than the pusher when the latter approaches the end ofsaid table.

5. A machine for stacking and delivering stiff sheets, which includes atable onto which said sheets are delivered in succession to form astack, means for slowing down the speed of movement of the sheets asthey pass onto the table, a stop in the path of movement of said sheetsand spaced above said table, and a pusher movable onto said table at oneend, beneath said stop, and below said table at the opposite end, forpushing batches of sheets from the bottom of a stack accumulatingagainst said stop.

6. A machine for stacking and delivering stii sheets, including a tableonto which said sheets are delivered in succession to form a stack, astop in the path of movement of said sheets and spaced above said table,a pusher movable over said table to force batches of sheets from thebottom of the stack beneath said stop, an endless chain for moving saidpusher over said table in one direction and back beneath the table inthe opposite direction, a motor for operating said chain, a motorstarting switch above said table, in the path of movement of the sheetsand operated by them, for starting the motor when the stack reaches apredetermined height, and a second switch for automatically stoppingsaid motor when said pusher reaches a predetermined position beneathsaid table.

7. A machine for stacking and delivering stii sheets, including a tableonto which the sheets are delivered, a stop in the path of movement ofthe sheets whereby the sheets accumulate as a stack, said stop beingspaced above said table, a pusher for delivering a batch of sheets fromthe bottom of the stack beneath said stop, means for slowing down thespeed of the sheets as thex,T pass onto the table, and means forspeeding up the delivered batch of sheets as they leave the table.

8. A machine for stacking and delivering stiff sheets, including a tableonto which the sheets are delivered, a stop in the path of movement ofthe sheets whereby the sheets accumulate as a stack, said stop beingspaced above said table, a pusher for delivering a batch of sheets fromthe bottom of the stack beneath said stop, means for adjusting theelevation of said stop so that its lower edge is but slightly higherthan the path of travel of the upper edge of the pusher when moving oversaid table, means for slowing down the speed of the sheets as they passonto the 8 table, a roller at the opposite end of the table and ontowhich the batch is delivered, and means for rotating said roller at ahigher peripheral speed than the rate of travel of the pusher.

9. An apparatus for forming and delivering batches of successivelydelivered stiff sheets, each batch being of a predetermined height, saidapparatus including a table, means at one end of said table forprojecting said sheets edgewise in succession onto the table, a stop inthe path of movement of said sheets, whereby a stack is piled up on thetable, the lower edge of said stop being spaced above the table to adistance equal to the height of the desired batch, a pusher movable oversaid table and beneath said stop, and of a height less than the spacingof said stop above the table by an amount less than the thickness of asheet, and means for starting the operation of the pusher when theheight of the stack exceeds the height of the desired batch.

10, A machine for forming and delivering batches of stili? sheets,including a table, means for delivering thereonto stii sheets insuccessiony each sheet being delivered on top of the preceding sheet, astopspaced above said table and vertically adjustable to a distanceequal to the height of a desired batch of said sheets, a pusher of aheight equal to that of the desired batch of sheets, and endlessflexible members in spaced vertical planes and connected to said pusher,each of said members having an upper run for moving said pusher alongsaid table to advance the sheet, push a batch beneath said stop, anddeliver it from said table, and a lower run disposed beneath said table.

NICHOLAS MCCLURE. SAMUEL D. STACY.

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